Fabrication of electronic components is principally performed on semiconductor substrates, such as single crystal silicon wafers. Processing steps involved in fabricating devices on a semiconductor wafer often entail the use of high temperatures, vacuum chambers, and highly reactive chemicals. Semiconductor wafer fabrication facilities are thus both expensive to build and operate.
The semiconductor substrate is a large portion of the cost of electronic devices, so cheaper substrates are desired. Unfortunately, the high temperatures and reactive chemicals typical of semiconductor wafer processing places limits on the choices of materials which can be used. For example, plastic substrates, while inexpensive, cannot handle high processing temperatures or certain chemical processes. Fabrication of devices on a plastic substrate is highly desired, for example, to enable lightweight, lower cost electronic displays. While some techniques for fabricating devices on plastic substrates are known, there is room for improvement in these techniques and the quality of devices fabricated. For example, finding materials which can provide high quality electrically active materials and be processed at temperatures compatible with plastic substrates has proven elusive.
Another factor affecting the cost of fabricating electronic devices is the complexity of the photolithographic processes used to pattern the various features of the devices. Recent efforts have focused on developing techniques to directly print the features of devices, for example, using ink-jet printing. While much success has been obtained with such approaches, printing of micro-features, for example having dimensions of 10 micrometers or smaller, has also proven elusive. Moreover, it is difficult to find suitable materials which can be applied with various printing processes. Accordingly, achieving devices having size or properties comparable to devices manufactured by semiconductor wafer processing have proven challenging.